Background and Purpose- Patients with
transient ischemic attack (TIA) and minor
ischemic stroke are at risk for early recurrent
cerebral ischemia.
Anticoagulants are associated with reduced recurrence but also increased hemorrhagic transformation (HT). The safety of the novel oral
anticoagulant dabigatran in
acute stroke has not been evaluated. Methods- DATAS II (
Dabigatran Treatment of
Acute Stroke II) was a phase II prospective, randomized open label, blinded end point trial. Patients with noncardioembolic
stroke/
transient ischemic attack (National Institutes of Health
Stroke Scale score, ≤9;
infarct volume, ≤25 mL) were randomized to
dabigatran or
aspirin. Magnetic resonance imaging was performed before randomization and repeated at day 30. Imaging end points were ascertained centrally by readers blinded to treatment. The primary end point was symptomatic HT within 37 days of randomization. Results- A total of 305 patients, mean age 66.59±13.21 years, were randomized to
dabigatran or
aspirin a mean of 42.00±17.31 hours after symptom onset. The qualifying event was a
transient ischemic attack in 21%, and
ischemic stroke in 79% of patients. Median National Institutes of Health
Stroke Scale (interquartile range) was 1 (0-2), and mean
infarct volume 3.2±6.5 mL. No symptomatic HT occurred. Asymptomatic petechial HT developed in 11/142 (7.8%) of
dabigatran-assigned patients and 5/142 (3.5%) of
aspirin-assigned patients (relative risk, 2.301 [95% CI, 0.778-6.802]). Baseline
infarct volume predicted incident HT (odds ratio, 1.07 [95% CI, 1.03-1.12]; P=0.0026). Incident covert
infarcts on day 30 imaging occurred in 9/142 (6.3%) of
dabigatran-assigned and 14/142 (9.8%) of
aspirin-assigned patients (relative risk, 0.62 [95% CI, 0.26, 1.48]). Conclusions-
Dabigatran was associated with a risk of HT similar to
aspirin in acute minor noncardioembolic
ischemic stroke/
transient ischemic attack. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02295826.